The "Hispanic paradox" refers to the concept that all-cause and cardiovascular (CV) mortality are widely thought to be lower in Hispanics, including Mexican Americans, than in non-Hispanic whites in the U.S. The data supporting this paradox are derived almost exclusively from vital statistics which are subject to various biases including ethnic misclassification and incomplete ascertainment of deaths, both of which tend to underestimate Hispanic mortality. Therefore, the possibility exists that the Hispanic paradox is an artifact. Cohort data with complete ascertainment of vital status have the potential of eliminating or at least markedly ameliorating most of these biases. The preliminary mortality data, based on 50,148 person-years of follow-up, suggest that all-cause mortality is actually higher in Mexican Americans than in non-Hispanic whites in San Antonio (odds ratio of 1.54). The plan is to perform a 15- to 24-year mortality follow-up with 92,164 person-years of follow-up and 907 deaths projected by the year 2003, to form a more precise estimate of the ethnic odds ratio. The additional number of deaths will also permit exploration of the potential time dependencies in the ethnic mortality ratio, and will allow examination of the effects of potentially explanatory covariates. These will include, in addition to the biochemical parameters, hemodynamic and anthropometric variables such as socioeconomic status, health care access and utilization and migrant status. Of the 5,158 individuals (approximately 65% Mexican American) in the original cohort, 3,666 were examined twice, 7-8 years apart. Therefore, it will be possible to examine the effects on mortality of changes in risk factors, e.g., whether weight change (voluntary or involuntary) influences mortality and whether the excess mortality in patients with impaired glucose tolerance is confined to those who convert to diabetes. There are also plans to examine whether Mexican-American diabetics have a higher mortality than non-Hispanic diabetics. Finally, there are plans to validate a sample of 200 Mexican-American and 200 non-Hispanic white death certificates by medical record review. The purpose of this project is to determine whether Mexican Americans, deemed to have died of cardiovascular causes based on medical record review, are more or less likely to have cardiovascular codes (ICDA 390-459) listed on their death certificates than non-Hispanic whites deemed to have died of these causes. The investigators note that this will aid in the interpretation of data relating to possible ethnic differences in cause-specific mortality based on death certificate coding.